such as dizziness, sickness or diarrhoea, then it is more than likely that B12 is unsuitable for your client, although this is extremely rare
[PubMed] [PMC] Hagstrm H, Adams LA, Allen AM, Byrne CD, Chang Y, Duseja A, Grnbk H, Ismail MH, Jepsen P, Kanwal F, Kramer J, Loomba R, Mark HE, Newsome PN, Rinella ME, Rowe IA, Ryu S, Sanyal A, Schattenberg JM, Serper M, Sheron N, Simon TG, Spearman CW, Tapper EB, Villota-Rivas M, Wild SH, Wong VW, Yilmaz Y, Zelber-Sagi S, berg F, Lazarus JV (2024) The future of International Classification of Diseases coding in steatotic liver disease: An expert panel Delphi consensus statement
Not everyone will be affected the same way so many people try an elimination diet, cutting out suspect foods one by one to see which may cause symptoms
PubMed Goldstein AL, Hannappel E, Kleinman HK